Alarm and control system for internal combustion engines



Aug. 13, 1935. G D PQGUE 2,010,960

ALARM AND CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed March 20,1934 7 Sheets-Sheet l Aug. 13, 1935. POGUE 2,010,960

ALARM AND CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed March 20,1934 7 Sheets-Sheet 2 INVENTOR Aug 13, 1935. G. D. POGUE 2,010,960

ALARM AND CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Mal-c320.1934 7 Sheets-sheaf, 3

J mom ACK da -Mum EKV/ INVENTOR Aug. 13,1935 e. D; POGUE- 2,010,960

ALARM AND CONTROL SYSTEM FOR INTERNAL COMBUSTIONBNGINES Filed March 20,1934 7 Sheets- Sheet 5.

INVENTOR e, n. POGUE Aug. 13, 1935.

ALARII AND coumon svs'rnu 'Fbn- INTERNAL COIIBUSTION'ENGINES Filed larch2o;'19s4 7 Sheets-Sheet 6 Aug. 13, 1935.

a. D. POGUE AND CONTROL SYSTBI FOR INTERNAL COIBUSTIOI ENGINES 7QSheets-Sheet 7 v Filed larch 20, 1934 Patented Aug. 13, 1935 PATENTOFFICE ALARM AND CONTROL, SYSTEM FOR INTERNAL COMBUSTION ENGINES GeorgeD. Pogue, New York, N. Y., assignor of one-half to Brooke L. Jarrett,Pittsburgh, Pa.

Application March 20, 1934, Serial No. 716,460

45 Claims. (01.123-198) tion through the speed-responsive unit of theThis invention relates to the operation of internal combustion engines,and is particularly applicable to the operation of internal combustionengines of the Diesel type., The present application constitutes acontinuation-in-part of my earlier filed application, Serial No.573,711, filed November 7, 1931.

In the operation of Diesel engines, there is a maximum speed beyondwhich it is both unsafe and undesirable for the engine to operate. Suchoverspeeding of the engine isgenerally due to some condition whichdemands that the engine be stopped at once. Certain other conditionsarise in the operation of the engine which require that theengine bestopped if the condition is not remedied within a reasonable length oftime. For instance, if there is a failure of lubrication, "or thepressure of the lubricant falls below a point of safety, the engine mayoperate for a few minutes without danger, but if the cause of thefailureof lubrication is not remedied within a few minutes, the engineshould be stopped.

Other conditions of fault may also be remedied within a reasonable timewhile the engine is running, but if they are not remedied the engineshould be stopped. In addition to failure of lubrication some of theother conditions are,- cooling water to the engine cylinders; failure ofcooling water to the air compressors; or failure of air pressure forinjection of fuel.

The present invention provides a mechanism wherein the overspeeding ofthe engine will result in the engine being stopped, and this ispreferably effected through the source of air supply to the enginecylinders. The invention further contemplates that upon failure of otheressential functions, such as those noted above, i. e., failure oflubrication, etc switch mechanism will be put into operation forshutting ofi the engine after a predetermined lapse of time, there beingan alarm and signal system to give notice instantly 'to the accompanyingdrawings in which 3 Figure 1 is a schematic diagram illustrating the'general scheme of the invention; Figure 2 is a detail view showing avertical secsystem Figure 3 is a detail view of the time switch leverand indicator;

4 Figure 4 is a front view showing how the va-. rious indicating devicesmay be conveniently disposed on a control panel;

Figure 5 shows a modified panel arrangement with a type of pressureresponsive switch different from that shown in Figure 1;

Figure 6 is a more or less schematic view showing the back of the panelof Figure 5, showing a somewhat modified circuit arrangement and adifferent form of speed-responsive circuit closing device; v

. Figure '7 is a detail view showing the end of another form ofspeed-responsive circuit closing devt'ce, together with circuit closingcontactors, a

' portion of the housingfor the contactors being *ing a modified form ofpressure responsive switch;'

Figure 13 Ban end view of the switch shown in Figure 12;

Figure 14 is another detail view showing still a further modifiedarrangement for the speed- ,rezponsive circuit closing contacts; and

Figure15 is a transverse section through the mechanism shown in Figure14; the view being substantially in the plane of line XV-XV of Figure14. In the drawings, which illustrate a present preferred embodiment ofthe invention, A designates the engine control unit; B is thespeed-responsive unit; 0 is the time switch; and D, E, F and G designatepressure-responsivecircuit-closing units.

I will first describe the control unit A. In the v specific embodimentshown, 2 designatesan air intake pipe comprising part of a Diesel orinternal combustion engine. In this air intake pipe is a" valve body 3.Within the body is a valve of any preferred construction having a shaft4 with anoperating lever 5. The outer end'of the lever .is weighted asindicated at 6. At I is a detent in which a latch or trigger 9 engagesfor normally holding the valve in open position. The latch 8 isoperatively connected with the armature of an electromagnet. I haveshown the electromagnet as comprising a solenoid 9.

The speed-responsive unit B is shown in the diagram in Figure 1 and indetail in Figure 2. It comprises a housing l9 within which is a verticalshaft H, the shaft being supported in bearings at each end of thehousing, and on the lower end of the shaft is a pulley l2 which isbelted or geared to the engine to be controlled. Mounted on the shaft IIwithin the casing to is a hub I3. Supported on the hub I3 is a metal cupl4 and opposite the cup i4 is a similar cup l5. These two cups formsockets for mercury tubes I6 and H, respectively. Each mercury tubecomprises a glass vessel having a body of mercury therein and having twocontacts in the outer end thereof. When the mercury tubes are revolvedat sufficient speed the mercury is thrown out by centrifugal force,closing the gap between the contacts to complete an electric circuit ashereinafter more fully described.

It will be noted that the mercury tube I1 is set at an angle more nearlyapproaching the horizontal than is the mercury tube 16. Because of thegreater inclination of the tube l6, the shaft H, as will be hereinaftermore fully described.

The time switch unit C comprises an electric motor 24, a speed reducinggear 25, and a switch arm and indicating lever 26 which is mounted onshaft 21 driven through the speed reducer. In Figure 3 the constructionof thisarm 26 is shown in detail. The pointer or arm 29 has a hubportion 28 through which the shaft 2'! passes. This hub portion has afriction key or shoe 29 therein which is urged into contact with theshaft 21 by means of a compression spring 30, the spring being heldunder pressure by a set screw 9!. This slip key or shoe provides adriving connection between the shaft 21 and the pointer 26 of suchnature that the pointer will ordinarily be moved upon rotation of theshaft 21, but the pointer may be rotated on the shaft to be set in apredetermined position. For settin the pointer a knob 32 is convenientlyprovided near the end of the pointer. Positioned along the path ofmovement of the pointer is a graduated segment 33 having a series ofnumbers thereon, which numbers apply to graduated markings on thesegment. When the motor 24 is operating it takes one minute for thepointer to travel from one marking to the next, the pointer moving inthe direc tion of the arrow in Figure 1. The numbers on thegraduatedsegment therefore designate minutes of time. The pointer 26 isa conductor, and a contact is provided at 34, as shown inFigure 1,against which the. pointer may move when it is at the limit of itstravel in the direction of the arrow to close a circuit, as hereinaftermore fully described.

Each of the pressure responsive units D, E, F and G are the same andlikereferencenumerals have been usedjto designate. the. correspondingparts. It will be understood that the showing in Figure 1 of these unitsis Purely diagrammatic. Eachunit comprises a mercury tube 35 having apair of contacts therein, these contacts being designated 35a and 35b.The tubes are support- This carrier 36 is actuated through a connection31 from a pressure responsive element, such as a Bourdon type expansionelement 38. A spring 39 acts in opposition to the pressure responsiveexpansion element 38. The numeral 40 designates a pipe through whichfluid pressure is communicated to the element 38, and 4! is a visiblepressure gauge for indicating the pressure in the element 38.

With this discussion of the apparatus, the circuits which correlate thevarious elements may now be described. It will of course be appreciatedthat instead of direct coupled circuits beed for tilting movement on apivoted carrier .36.

ing used, it is within the skill of an electrician to 20 substituterelay circuits where it is desirable to vuse currents of low magnitudein the control elements themselves. The circuit through the solenoid 9is to be closed at once upon overspeeding of the engine and is to .beclosed after a lapse of time upon failure of anyone of several difiefentfunctions, as hereinbefore stated. For energizing the magnet 9 uponoverspeeding of the engine, the circuit may be traced from one side of acurrent supply line 42 through wire 43, sole,- noid 9, wire 46, brush 2|of the speed-responsive unit B, ring i8 and wire .45, to contact lfid ofmercury tube H6. The other side of the circuit comprises mercury tubecontact l6b, wire 46, the middle slip ring 20, brush 23, and wire 41back to the outer side of thecurrent supply line 42a.

When the shaft H is revolving at such speed that the mercury in the tubeI6 is thrown out to the end of the tube, the solenoid 9 will beenersized to lift the latch armature 8 out of the de tent I, whereuponthe weighted lever 5-6 will drop down to close the air intake valve tothe engine. While it is obvious that instead of cutting off air intakesome other function of the engine could be controlled, it is especiallydesirable that t'he engine may be stopped through the cutting ofi of theair to the cylinders. For instance, the air in an" engine room maybecome highly charged with hydrocarbon vapors, as for instance, from thebreaking of a gas pipe.. If the valve 3 were in the fuel line it will beseen that even after the fuel supply were shut off the engine wouldcontinue to draw in carbureted air from the engine room and'op'erate onthis mixture. This is particularly likely to happen in the case of ahigh compression engine such as a Diesel engine. The shutting off of theair supply, instead of controlling the engine in any other way,therefore has particular advantage.

The other circuit for energizing the solenoid 9 is from one side of thecurrent source of sup ply 42, through wire 43, solenoid 9, wire 44 andwire 48, to contact 34. The other side of the circuit comprises theindicator switch arm 26, wire 49 and wire- 41 back to the other side ofthe source of current supply 42a. It will be seen that the solenoid 9can be energized through this circuit only when the motor 24 has beenenergized to move the switch arm 26 'into contact with the contact 34.The circuit for the motor 24 comprises wire 50 leading from one side ofthe current supply 42 to the motor 24, through the motor 24 .to wire 5!and wire 52. The various units D, E, F and G are in parallel, and theunits is apt to be below normal and is not built circuit may besimilarly traced through any one of these units. From wire 52 thecircuit leads through an indicator lamp 53 and a flexible connection 54to mercury tube contact 35b. The other side of the circuit is frommercury tube contact 35a through flexible connections 55,

wire 56, brush 22, 11 ring contact l3, wire 51,- to one of the mercurytube contacts l'la. A circult is completed by mercury tube contact llb,

mercury tube I'I, wire 58, wire 43,- slip ring contact 23, brush 23, andwire 41 back to theother side of the line 42a. While there is a separateindicator lamp 53 for each of the units-D, E, F and G, the circuit mayinclude also an electric horn or audible signal 59 in parallel with themotor 24. The operation for this part of the circuit may now befollowed. For the purpose of illustration, it may be assumed that pipe43 and gauge 4| of unit D respond to pressure in'the lubricating systemof the engine. Gauge and pressure responsive element 38 of unit Erespond to pressures in the cylinder cooling water system. The unit Fresponds to water pressure for cooling the compressors, while unit Gresponds to the pressure of the air for fuel injection. When the engineis started, some or all of these pressures may be below normal.- Thearrange-.

ment of the mercury tubes D is such that when pressure in the expansionelement 38 is below normal, the tube 35 is tilted down to a positionwhere the mercury in the tube closes the gap between the contacts 3511and 35b. When the pressure increases to normal, the position of the tubeis elevated to a point wherethe circuit is open" between the contacts35a and 35b. Assuming first that the pressures are normal and the engineis operating at normal speed the mercury in the tube l1 closes thecontact between "a.

and Ilb, butthe circuit in the motor 24 is not completed because withnormal pressures in the expansion elements 38 of units D, Ef F and G,the mercury tubes 35 are elevated and the chcuit is broken between.contacts 35a'and 356. If, however, pressure in one of these elementsdrops below normal, the tube 35 drops down, completing the circuitthrough the motor 24 and also through the visual signal 53 and theaudible signal 59. l

Thus with a failure of pressure in any one of the units, an audiblesignal is sounded to attract the attention of the operator, a visualsignal is displayed showing just which function is at fault, and themotor 24 starts to move the switch arm 26 toward the contact 34. Themachine attendant is" thus given a period of time in which to attempt tocorrect the faulty apparatus before theswitch lever 26 engages thecontact 34 to energize the solenoid 3 and stop the engine. This lapse oftime also gives t attendant an opportunity to start an emergen unit inthe event he sees that the fault cannot be corrected, within theallotted time. The numbers on the segment 33 are so positioned as toshow the number of minutes that the machine will continue to uperate. Ifthe fault is corrected before the arm 26 reaches contact 34 and normalpressure restored in that expansion element 33 in which it had dropped,the motor circuit will be broken by the raising of the mercury tube 35.The operator may then take hold of the knob 32 and 'u'p until the enginehas attained its operating speed. If it were not for the mercury tubeII, the motor circuit 24 would be 'closed when the machine is stopped orwhen it is just starting,

and before normal pressures have been reached. Since, however, thecircuit of the motor 24 is only closed when the mercury in tube lIimmerses the contacts Ila and I'll), the motor cannot be energized untilthe shaft Ii has reached -a'-predetermined speed of rotation. If by ,the

time the shaft i I, driveh from the engine, reaches its normal operatingspeed the pressure in one or more of the units 38 has not been built upto normal, the circuit through the motor 24 will be closed, because if,when the engine speed gets up to normal, pressure in any of the units D,E, F and G is not up to normal, something is the matterrequiring-attention.

' In Figure 4 I have indicated how the various indicating and pressureresponsive elements are mounted on a control panel. In this view,designates a panel having a plurality of transparent signs 6| thereon,which signs have appropriate lettering and behind which the signal lamps53 for .the respective units are located. The circular cases, designated62, are adapted to house the pressure gauges 4| while the circular cases63 house the pressure responsive mercury tube devices, these beingconstructed in a very compact manner, which is at present known to theart. The time switch unit C is located in the base of the panel, asindicated at 64, thereabeing a hinged glass door through which theindicator is visible and through which access may be had to theindicator 26 for resetting it.

The system provides for the complete super- .vision of an internalcombustion engine power plant, affording instant stoppage againstoverspeed and affording signals against various failures, such asfailure of the power plant, with the stopping of the power plant in apredetermined time if such failures are not corrected, and before theengine has operated long enough to do any serious damage' The number ofunits D, E,

F and G may be varied according to the number of difierent parts of thepower plant that the system is to be made responsive to. The system,

moreover, prevents premature'operation of the .for portable powerplants, especially the power plants used on boats and other-floatingequip ment. The arrangement shown in Figures 5 to 13, inclusive,illustrate a somewhat more simple and more practical embodiment of theinvention, and one which is more useful for power plants, on irehicles,and on boats and other floating units. In the embodiment shown inFigures 5 to 13, inclusive, I have illustrated the panel as having afewernumber of pressure responsive switches than in the systempreviously described,

but it will be understood that the number of switches can be increasedand varied according to the needs of. any particular installation.

In Figures 5 and 6, the numeral 10 designates the control panel. It isprovided at the top with a window H for a pilot light. 12 designates thesupport for the pilot light. Below the pilot light is a window I2 whichmay bear a suitable by a. compression spring 92.

of the lever. a transversely extending metallic spring 98 having contactbuttons 95 at theppposite ends there- .of. These contact buttons areadapted to co- .connector posts 91.

Back of this window are one or more sockets M and 15 having lampstherein. Under the window 14 is a pressure gauge or indicator I6, andbeside the pressure indicator is a pressure-responsive circuit closer11. The two pressure-responsive devices I6 and H are, connected to acommon pipe 18 that may lead to the source of fluid pressure to whichthe switch I1 is intended to respond. For example, it may lead to thesource of water supply for the cooling system of .the engine to, becontrolled.

Similar arrangements may be duplicated on the panel. For instance, inFigures 5 and 6, there is a second window M, a second pressure gauge I6,a second pressure switch TI, and lamps 18'. The pressure gauge and thepressure-responsive switch 76' and 11', respectively, are connected to acommon pipe Til which leads to another source of fluid pressure supplyimportant in the operation of the engine to be controlled, as forinstance; the source of lubricating pressure;

On the panel below the mechanism described, there is a time switch unitC corresponding generally to the unit C'oi Figure 1.

The system includes in addition to the panel and the time switch unit,amechanically operated valve A corresponding to the valve A of Figure land the speed-responsive circuit closer B corresponding in function tothe speed-responsive circuit closer B of Figure l. I

The pressure-responsive switches 11 and i1 are shown in detail inFigures 12 and 13. Each switch comprises a body member 88 having achamber 8| therein. The body member is provided with a cover 82 andconfined between the cover and the member 88 is a relatively heavyrubber or other flexible diaphragm 83. Resting on the top oi. thediaphragm 83 is a disc 84 having astem 85 projecting through an openingin the cover 82. The chamber 8| is provided with a fluid pressure inletopening 88. Carried on the cover member 82 is an upright support 87 onwhich is pivotally carried a lever 88, one arm of which is preferablyconsiderably longer than the other arm. The shorter arm has anadjustting screw 89 thereon which bears against a spherical surface 90on a member 9| supported The compression spring 92 is retained on thecover 82. The projection 85 on the disc 84 carries a bearing member 83which contacts with the under side of the long arm of the lever 88 closeto thepivot point The outer end of the arm carries operate with contactsurfaces 96 on a pair of The spring 94 constitutes a conductor from onecontact 95 to the other. The device, in efiect, provides a. single poledouhie-contact switch.

When a normal fluid pressure is maintained in the chamber 8I,-thediaphragm 83 is flexed upwardly, lifting the disc at, raising the longarm of the lever 88 against the compression of the spring 92 to'a pointwhere the contact buttons 85 are free of the contact surfaces 96. Thethrow of the switch lever is limited by the clearance oi the lever 88forces the long arm of the lever down. to circuit closing position. Thethrow I aomeeo legend, as described in connection with Figure 4:.

of the lever is adjusted so that as the contact buttons 95 bear againstthe buttons 95, the spring 94 will be flexed very slightly to thestraight line position indicated in dotted lines in Figure 13. Thisflexing of the spring 94 causes a'slight movement of the contacts 95 onthe surface 86, assuring that a good electrical contact will be madewhen the switch closes.

It will be observed that the switch is moved to open position by themaintenance of a fluid pressure in the chamber 8| while the compressionspring 92 opposes the opening movement and biases the switch to closewhen the pressure in the chamber falls below a predetermined minimum.The switch can be set to operate in any position, not being responsiveto gravity and not depending upon any liquid for closing the contacts,it is not afl'ected by any rocking movement such as is encountered onboats and the like. Adjustment of the screw 89 provides for the properpredetermined relation between opening pressure and the closing pressurefor the switch, inasmuch as adjustment of the screw varies the pressureon the spring 82.

It will be seen that these switches may be substituted for the mercuryswitches of Figure 1 above described.

The magnetic valve unit A is illustrated as being of a well knowncommercial construction forming no part of the present invention. Inthis respect, it is slightly difierent-irom the arrangement shown inFigural wherein the counterweighted lever is held byanelectromagnetically operated trigger. In Figure 6, 2' corresponds tothe pipe 2 of Figure l. The valve is designated as 3'. It hasga. steml.'. -I have conventionally indicated at I88 a casing within which is anelectromagnet for closing-thevalve whereby the valve is made directacting instead-of employing a gravity lever as wn in Figure 1. Aspreviously stated, electro agnetic valves of this type are common in theart and form no part per se of the present invention.

The speed-responsive unit B is arranged to perform the same function asthe unit B of Figure 1. However, in the unit B, mercury contacts havebeen eliminated, and the unit responds entirely to the speed at whichthe unit is driven. Since it does not depend upon mercury or otherfluid, it can be more satisfactorily used on boats and in other portablepower plants than can the arrangement shown in Figure 1.

The unit B comprises a speed-responsive unit using centrifugal weights.The particular construction of the governor per se forms no part of theinvention. The specific governor illustrated in Figure 11 is known asCl'ass 1800" manufactured by Pickering Governor 00., of.Port1and,

Conn. It comprises a casing I 0| in which is a rotatable shaft I02having a pulley I03 at its outer end which is adapted to be driven fromthe engine to be controlled. The shaft, carries centrifugally responsiveweights I84 pivotally supported at 35. The weights I04 are essentiallyin the shape of bell cranks and they are provided with pins J88 whichengage an annular groove I01 in a collar I88. Carried on the inner endof the shaft I82v passing through the upper part of the casing IOI is atransverse shaft I89. It is provided with anann M8, the arm IIO having apin III that engages in an annular groove in the member 2 associatedwiththe collar I08. The arrangement is such that when the weights I84move out under the influence of centrifugal force, the collar I08will-be-mcvedto thelettasviewed in Figure 11.

- movement of the collar. Y I

According to the present invention, I provide a casing I I5 on theoutside of the governor casing I I and the end of the shaft I09 extendsinto this casing. On this shaft there are'two cam bodies I I6 and I Heach of which is adjustable on I the shaft and each of which has anadjustable cam nose member similar to the member- I I8 of Figure 10.Pivotally supported within the casing II on a transverse pin I I9 aretwo spring contact members I20 and Hal. The member I20 extends over thecam I I5 and the member I2I extends over the cam member I. The springcontact members I20 and I2I are provided with wearing blocks I22 formedof insulating material. Positioned over the free ends of the springcontact arms I20 and I2I are adjustable contact members I23 and I24,-

contact I23 being over the arm I20 and contact I24 being over the armI2I.

The arrangement is such that when the shaft I09 is rotated in acounter-clockwise direction, as

7 it is when the engine comes up to speed, the cams H0 and III willyberotated. The cam III is slightly out of phase with the cam IIS and isrotated with respect to cam I I6. The setting of the,

cams is such that when the engine reaches approximately 80% of itsnormal speed, the contact arm I20 will be lifted to make contact withthe contact I23. This contact will be maintained when the-engine reachesnormal speed. If the engine goes above normal speed, cam III will be'rotated to a positionwhere it lifts the contact I2I into engagement withthe contact member I24. The two cams and their contact arms are arrangedto perform the same function as the two mercury tubes in the unit 13 ofFigure 1 Adjustment for the critical speed at which each contact is tobecome operative may be determinedJflrst by the setting of the member H6or III on the shaft I09, and further adjustment can be obtained by theadjusting of the nose member III with respect to the cam body on whichit is mounted. As shown in Figure 10, the nose member H0 is providedwith arcuate slots to enable adjustment of this member with respect tothe screws ,which hold it on the cam body. Adjustment of the cams givesthe same range of control that adjustment of the angles of the mercurytubes gives in the unit B of Figure 1.

I have also shown in Figure 6 a slightly different time switcharrangement from that described in connection with Figure 1. On thefront of the panel I0, there is a'graduated segment similar to thatshown in Figure 4. It is preferably graduated in numerals indicating theminutes, as previously explained in connection with Figure 1. On thefront of the panel I0, there is an indicating arm I25 corresponding tothe indicator 25 of. Figure 1. The arm I25 is carried on a shaft I20driven by a clock mechanism I21. This clock mechanism is conventionallyindicated in Figur 6. The shaft I26 also carries a contact arm I20adapted to move toward a stationary contact I25. The clock may be anelectrically operated clock or a spring-operated'clock. Its operation iscontrolled by a trip lever I30. Mounted on the back of the panel is anelectromagnet I 3| having an armature I32 with a projection I33 thereonengaging under the detent I30l- When the electromagnet I3I is energized,the armature I32 is lifted, raising the detent I30 'to set the clockinto operation.

Below the electromagnet I3I I have shown an electromagnetic relay I34.'At I35 there is an electric horn or other audible signaling devicecorresponding to the signal 59 of Figure 1. The circuits for the variousdevices maynow be traced. The two main lead wires I38 and I39 areconnected with any suitable source of power .X. Wire I38 leads to aconnector I39 on the speed responsive switch mechanism of unit B. Fromtheconnector I38 there are two wires I40 and MI leading to the springfingers I20 and I2I, respectively. from the contact I23 is a wire I42that leads directly to the pilot l ght I2. Wire I43 leading away fromthe pilot light connects to the other side of the supply line I39. Thepilot light I2 is thus lighted the entire time that the switch I20, I23is closed. As previously explained, this switch closes when the enginereaches about 80% of its normal speed and remains closed as long as theengine is operating at or above 80% of its normal speed. Another wireI44 leads from the wire I42 to wire I45. Wire I45 has one branch I46leading to one contact of the pressure switch 11. It has another branchI46 leading to one side of the pressurerespons'ive switch unit .11. Theother side of the switches TI and II are connected through the lamps I5and I5 to wires I4'I'and I4'I, respectively, leading into the wire I48.Wire I48 is connected to one side of the relay I34. The other side ofthe relay. I34 is connected through wire I43 with the line I39. The wireI45 has another branch I50 connected to one side of the electromagnetI3I. The other side of the electromagnet I3I is connected through wireI5I to wire I52. Wire I52 goes to one contact of the relay I34.Themovable contact of the relay I34 is connected through wire I53 to thewire I 49' going back to the line I39. The wire -I52 is also coupled toone side of the audible signal device I35 while the other side of theaudible signal device is connected to the wire I45.

The operation of the system may now be followed. The speed-responsiveunit B, of course, is connected with the Diesel engine or other powerplant or other device to be controlled. When the engine reaches about80% of its normal speed, the cam IIO will be rotated to a point wherethe switch I20-I23 is closed. By the time the engine reaches this speed,the cooling water andthe lubricating oil should be up to a pressuresuflicient to raise the diaphragm 03 of the pressure-responsive switchand maintain the contacts 95 out of contact with the terminals 96 of thepressureoperated switches. As long as the engine speed does not exceed apredetermined maximum, and as long as the fluid pressure-responsiveswitches 11 and 11' are open, nothing occurs except that the pilot lampI2 is lighted through the circuit comprising the speed-responsive switchI20- I23, wire I42, lamp I2, wire I43, and back to the other side of theline I39.

' If the fluid pressure fails in either of the switches 11 or II, thecircuit is closed across the terminals of theswitch. If, for instance,the water pressure drops below normal, the switch "will close, in,whichcase a circuit will be completed from the line I38 through thespeed-responsive, switch I20-I23 and wire I42 to wire I44. From wire I44the current path travels through wire I45 through wire I46.across thecontacts of the pressure-responsive switch 11 I48, the winding of therelay I34 and wire I49 to the other side of the line I89. The completionof this circuit causes the visual signal at 14 to be lighted, indicatingto the attendant that the wa ter pressure is defective. completion ofthe circuit energizes the relay,

closing the circuit througlrthe audible signal I35. This serves toattract the attention of the attendant to the board. The closing of thecircuit through the light 15 (or 15') also completesra' This starts theclock into operation and the indicating hand I25 at the front of thepanel starts to move toward the contact I29. If the operator can correctthe difliculty before the contact finger I28 engages the contact I29,the pressure-reg sponsive switch 11 will open, and all of the circultswill be restored to the normal condition. The opening of the circuitwill also cause the electromagnet I3I to release its armature I33 andlet the clock detent I30 drop back to its normal position. If thedifiiculty is not corrected by the time the contact finger I28 engagesthe contact I29, a circuit is immediately closed from the line I38through wire I55, contact finger I28, contact I29, wire I56, wire I51,to the electromagnetic valve I00. i I

From the other side of the electromagnetic valve, the current path iscompleted to the other side of the line I39. The energizing of the valveof the electromagnetic valve immediately closes the valve. If this isthe air intake valve of a Diesel engine; the'eng'ine is immediatelystopped. The stopping of the engine, of course, stops thespeed-responsivedevice B, the cam I I6 drops back to open the switchI25I23 whereupon the pilot light, the visual signal and the audiblesignal are all de-energized, and the clock I21 is stopped by theenergization of the electromagnet I9I.

I In the case of the engine reaching a speed which I is above apredetermined maximum, the circuit will be completed from one side ofthe line I38 through the speed-responsive switch I2I to the wire I24, towire I51. From wire 051, the current flows through the electromagneticvalve to the other side of the line I39. On a condition ofover-speeding, the engine is 'thus immediately stopped.

It will be seen that the general functioning of the system as thusdescribed is substantially the same as the system described in Figure 1.However, by the substitution of pressure-responsive switches, andspeed-responsive circuit closers which avoid the use ofmercury or otherfluid, the system is better adapted to use on moving power plants,particularly those on boats and other floating equipment, such asdredges and the like.

In Figures 14 and 15, there is illustrated a slightly modified form ofspeed-responsive circuitclosing device adapted to the purposes of thepres- V ent invention. In these figures, the governor is of the sametype as that described in connection with Figures. '1 ton, inclusive.There is a governor casing I60. At the top of the casing, there is atransverse shaft I6I corresponding to the shaft I99 of Figure II. Theshaft I6I is rocked about its axis upon operation of the governor.

At the same time, the

through the lamps 15 to the wire I41. From the wire I41, the currentpath is'through' the wire" Secured to the casing'lfiil is a box orhousing I62,

and the end of the shaft I6I projects into this housing. Secured to theend of the shaft IGI within the housing is an arm I63 having an outerportion I64 thereon which is insulated from the body of the arm asillustrated. This outer portion of the arm carries two brushes I65 andI66.

brush I65 rides onto the conducting portion I61a of its" segment. Thebrush I66. however, still remains on a non-conducting part of itssegment. When the brush I65 rides onto the conducting porticn 261a, acircuit may be closed from the connector block I69 through flexible wireI16 to the brush 65. From this brush the circuit is completed throughthe conducting portion I61a and wire I1I to connector block I12. If thegovernor is operated above a predetermined normal speed, the arm I53 isrocked still further, bringing the brush I66 onto the conducting portionI68a. of its segment I68. Then a circuit may be completed from theconnector block I69 through the wire I19, brush I66 and conductingsegment I68q to wire I13 to the connector block I14.

This arrangement provides a simple speed-responsive circuit closer inwhich no circuits are closed below a predetermined minimum speed,wherein one circuit is closed above minimum speed, and a second circuitclosed above a maximum normal operating speed. It will be readilyunderstood by those skilled in the art how this type of mechanism may besubstituted for the double cam arrangement of Figures '7 to 9,inclusive.

As previously indicated, the invention is not restricted to Dieselengines, or internal combustion ly Figure l, and that variousmodifications and changes in the construction of the particular elementsis contemplated under the invention.

I claim: v 1. An engine control system comprising an electromagneticengine control iuiit, a speed-responsive unit driven by the enginehaving. :1 normal speed circuit closer and an'over-speed circuit closer,a pressure-responsive circuit closer in series with the normal speedcircuit closer, a time switch unit having an operating means in serieswith said normal speed circuit closer and said pressure-responsivecircuit closer and havingcontacts operated by said operating means forclosing a circuit from a source of current through said electromagneticengine control unit, and a circuit through which said over-speed circuitctoser and said electromagnetic engine control unit; are connected witha. source of current.

-2.'An engine control system comprising an electromagneticengine'control unit arranged to stop an engine upon energizationthereof, a

speed-responsive circuit closing device adapted to close a circuit whenthe engine is operating at normal speed, a pressure-responsive unit inseries with said speed-responsive unit, a source of current, and anelectrically energized normally open time switch mechanism in circuitwith the control unit and with the source of current for energizing thesame when it is closed and havin means for closing the same connected inseries with and under the control of said speed-responsive andpressure-responsive units, said last named means, the speed-responsiveunit and the pressure-responsive unit being connected in series with thesource of current.

3, An engine control system comprising an electromagnetic engine controlunit arranged to stop an engine upon energization thereof, a speedresponsive circuit closing device adapted to close a circuit when theengine is operating at normal speed, a pressure-responsive unit inseries with said speed-responsive unit, an electrically energized timeswitch mechanism connected with the control unit for energizing the sameand under the control of said speed-responsive and pressureresponsiveunits, and a second speed-responsive element directly controlling theelectromagnetic unit andarranged to close a circuit therethrough uponover-speeding of the engine.

:5 4, An engine controlling system comprising an engineoperated shafthaving acentrifugal circuit closing means thereon operable to close acircuit at normal engine. speed and a second circuit closing meansoperable to close a circuit only at super-normal engine speed, anelectromagnetic engine control unit directly in circuit with said secondcircuit closing means, and a time switch and pressure-responsive switchthrough which said firstcircuit closing means energizes the con trolcircuit.

5....Acontrol mechanism for internal'combustion engines comprising anair intakepipe for supplying air to the cylinders of the engine. a valvein said pipe adapted to close the same against the passage of airtherethrough and which is normally open,'an electromagnetically operatedmeans. through which the closing of the valve may be-eflfected, acircuit closer operative only after a predetermined time interval inseries with said electromagnetic means, and a pressureresponsive unitfor controlling the actuation of the circuit closer.-

6. hcontrol mechanism for internal combus ticn engines comprising an airintake pipe for supplying air to the cylinders of the engine, a valve insaid pipe adapted to close the same against the passage of airtherethrough and whicheisnormally open, an electromagnetically operatedmeans through which the closing of the valve maybe effected, a motoroperated circuit closer irrserles with said electromagnetic means, apressure-responsive unit for controlling the motorofsaid motor operatedswitch, and a speedresponsive switch in circuit with saidpressureresponsive means arranged to prevent the closing of the switchmotor circuit until the engine has reached a predetermined speed;

'7. An engine control system comprising-a plurality ofpressm-e-responsive circuit closing units connected in parallel andadapted to respond to various pressure conditions in an engine to becontrolled, a speed-responsive circuit closer adapted to be driven bythe engine under control in series with said pressure-responsive circuitclosing devices and arranged to close a circuit only when the engine isoperated at a'predetermined speed, a time switch in circuit with saidspeed-responsive circuit closer, and an electromognetic engine controldevice under the control of said time switch. a

8. An engine control system comprising a plurality ofpressure-responsive circuit closing units connected in parallel andadapted to respond to various pressure conditions in an engine to becontrolled, a speed-responsive circuit closer adapted to be driven bythe engine under control in series with said pressure-responsive circuitclosing devices and arranged to close a circuit only when-the engine isoperated at a predetermined speed, an electric motor connected with saidspeed-responsive circuit closer, a switch op.- erated by the motor, andan electromagnetically controlled engine stopping unit in circuit withsaid switch.

9. An engine control system comprising a shaft adapted to be rotated bythe engine under control, a pair of mercury tubes on the shaft one ofwhich is set more nearly vertical than the other and having contactstherein, an electromagnetically operated engine stopping unit, a circuitconnecting said engine stopping unit and themercury ,tube which ismostnearly vertical in serieswith asource of power, a time switch forgine stopping unit with a source of power after a predetermined timeinterval, a pressure-responsive circuit closer for operating the timeswitch and responsive to apressure condition in the engine to becontrolled, and a circuit connecting said pressure-responsive circuitcloser in series with the other mercury tube on said shaft whereby thetime switch can only be opera when saidshaft is rotating.

10. an engine control system comprising a shaft adapted to .be rotatedby the engine under control, a pair of mercury tubes on the shaft one ofwhich is set more nearly vertical than the other and having contactstherein, an electromagnetically operated engine stopp unit, a circuitconnecting said engine stopp unit and the mercury tube which is mostnearly vertical in series with a source of power, a time switch forconnecting said electromagnetically operated engine stopping unit with asource of power after a predetermined time interval, apressure-responsive circuit closer for operating the time switch andresponsive to a pressure condition in the engine to be controlled, and acircuit connecting said pressure-responsive circuit closer in serieswith the other mercury tube on said shaft whereby the time switch canonly be operated when said shaft is rotating, said pressure-responsivedevice being arranged to close a circuit upon a decrease in the pressureof the fluid to which it responds.

11. An arm safety stop system for a power mechanism comprising a stopunit for the power mechanism. electromagnetic means for operating saidunit to stop the mechanism, a fluid pressure system for supplyinglubricant and/or cooling water to said mechanism, a centrifugal circuitcontroller adapted to be driven by said mechanism, a pressure-responsivecircuit closer in said fluid pressure system and in circuit with saidcentrifugal circuit controller, and which closes a circuit through saidcentrifugal circuit controller upon a failure of pressure in said fluidpressure system, a time switch mechanism controlled by the circuitthrough said centrifugal circuit controller and said pressure-responsivecircuit closer,

said time switch being connected in circu with mum; saidspeed-responsive switch being connected in series with the fluidpressure switch, and an electrically operated signal in circuit withsaid speed-responsive and fluid pressure circuit closing units.

21. An "engine control system comprising an electromagnetically operatedengine cut-oflf unit,

-a speed-responsive circuit closing unit driven by the engine to becontrolled, 9. fluid pressureresponsive switch unit adapted to beconnected to a source of fluid pressure, the maintenance of which isincident to the continued operation oi. the engine and which switch isheld open by a predetermined fluid pressure and which is closed upon areduction of pressure below the predetermined minimum, a time switchunit, and

28, a circuit connecting the speed-responsive switch and the fluidpressure-responsive switch in series with the time switch unit, andanother circuit connecting'the time switch unit and theelectromagnetically operated engine cut-ofl unit.

An engine control system comprising an I electromagnetically operatedengine cut-oil unit,

a speed-responsive. circuit closing unit driven by the engine to becontrolled, a fluid pressureresponsive switch unit adapted to beconnected to a source or fluid pressure, the maintenance of which isincident to the continued operation f the engine and which switch isheld open by a predetermined fluid pressure and which is closed upon areduction of pressure below the predetermined minimum, a time switchunit, a

- circuit connecting the speed-responsive switch and the fluidpressure-responsive switch in series with the time switch unit, anothercircuit connectmg the time switch unit and the electromagnetlcallyoperated engine cut-oi! unit, and a circuit including saidspeed-responsive switch and said fluid pressure switch and said sign ldevice- 23. An engine control system comprising an electromagneticallyop rated engine cut-oi! uni a speed-responsive circuit closing unitdriven by e the engine to be controlled, a fluid pressureresponsiveswitch unit adapted to be connected to a source of fluid pressure, themaintenance of which is incident to the continued operation of theengine and which switch is held open by a predetermined fluid pressureand which is adapted to close upon a reduction in pressure below thepredetermined minimum, a time switch unit, an electric means in circuitwith the speedresponsive unit, fluid pressure-responsive circuit closingunits for setting the time switch into operation, and a circuitconnecting the time ,switchand engine cut-oi! whereby the closing of thetime switch effects the stopping of the engine.

24, An engine control system comprising an electromagnetically operatedengine cut-oi! unit, a speed-responsive circuit closing unit driven bythe engine to be controlled, as fluid pressureresponsive switch unitadapted tobe connected to a source of fluid pressure, the maintenance ofwhich is incident to the continued operation of the engine and whichswitch is held open by a predetermined fluid pressure and which isadapted'to close upon a ie'dnetioiiifi below the predeterminedminimummtiineswitch and other means effective only when the engine hasreached a predetermined speed for operating the engine stopping unitafter a predetermined time following a failure of a predetermined fluidpressure supply to the engine being controlled by the engine stoppingunit.

26. In a power plant system, an engine stopping unit, means operable toactuate the engine stopping unit upon overspeeding of the engine, andmeans operable only when the engine is running and upon a failure of apredetermined fluid pressure in the power plant system for stopping theengine only after a predetermined time interval following the failure orsaid pressure.

27. In' a power plant system, an engine stopping unit, means operable toactuate the engine stopping unit upon overspeeding of the engine, meansoperable only when the engine is nmning and upon a failure of apredetermied fluid pressure in the power plant system for stopping theengine only after a predetermined time interval following the failure ofsaid pressure, and means for indicating the failure of pressure prior tothe stopping of the engine. r

28. In a. power plant system, an engine driven speed-responsive unithaving two circuit closing devices thereon, one of which functions whenthe engine attains a predetermined minimum speed and one of whichfunctions only when the engine exceds a predetermined maximum speed, anengine stopping device directly connected with said maximum speedcircuit closing device for stopping the engine when an overspeedcondition is reached, and means in circuit with said firstmentionedcircuit closing device which is operative when the engine attains apredetermined minimum speed for indicating a failure of pressure in thepower plant system only after the engine has reached said predeterminedminimum speed. I

29. In a power plant system a speed-responsive unit having two circuitclosing devices, the flrst after a. predetermined lapse of time.

30. In a power plant system in which various fluid pressures have to bemaintained after an engine reaches a predetermined speed, thecombination with a plurality oi. pressure-responsive switches connectedin parallel, of a speed-responsive switch connected in series with eachoi the pressure-responsive switches, and a signal device iii circuitwith each of the'pressure-responsive switches and with saidspeed-responsive switch speed.

31. The combination with a fluid supply system for an internalcombustion engine, of means responsive to variations in pressure in saidsystem, signal means governed by said first means for indicating anabnormal pressure condition, and means whereby said second means may berendered inoperative while the power plant is inoperative and until thepower plant reaches :3. normal operating speed.

, 32. The combination with a fluid supply system for an internalcombustion engine, of means responsive to variations in pressure in saidsystem, and means controlled by said first means for closing down theplant only after a predetermined definite time interval following anabnormal pressure condition in said system.

33. The combination with a fluid supply system forming part of aninternal combustion engine, of means responsive to variations inpressure in said system, signal means governed by said first means forindicating an abnormal pressure condition, and means controlled throughsaid first means for closng down the plant only after a predeterminedtime interval following'the operation of said signal means.

34. The combination with a fluid supply system for an internalcombustion engine, of circuit controlling means connected to said systemand responsive to an abnormal pressure variation in said system, andmeans controlled by said circuit controlling means for closing down thepower plant only after a predetermined time interval following anoperation of said circuit controlling means in response to an abnormalpressure condition in the system, said means including a cut-off deviceand a delayed acting control element therefor.

35. The combination with a fluid supply system for an internalcombustion engine, of circuit controlling means connected to said Systemand responsive to an abnormal pressure variation in said system, meanscontrolled by said circuit controlling means for closing down the powerplant only after. a predetermined time interval following an operationof said circuit controlling means in response to an abnormal pressurecondition in the system, ands speed responsive unit for controlling said-circuitcontrolling means whereby said circuit controlling means isrendered effective only after the plant has reached apredeterminedoperating speed.

36. The combination with a fluid supply system for an inte'rnalcombustion engine, of circuit controlling means connected to said systemand responsive to an abnormal pressure variation in said system, meanscontrolled by said circuit controlling means for closing down the powerplant only after a predetermined time interval following an operation ofsaid circuit controlling means in response to an abnormal pressurecondi-- tion in the system, said means comprising an engine cut-offdevice and a delayed acting control unit therefor and signal meanscontrolled by said circuit controlling means and rendered operativeimmediately upon actuation of said circuit controlling means to indicatean abnormal pressure condition.

37. The combination with a fluid supply ystem sponsive to an abnormalpressure variation in.

said system, means contrdled by sin circuit controlling meansfor-closing down the power plant only after a predetermined timeinterval following an operation of said circuit controlling means inresponse to an abnormal pressure condition in the system, signal meanscontrolled by said circuit controlling means and rendered operativeimmediately upon actuation of said circuit controlling means to indicatean abnormal pressure condition, and a speed responsive unit for con,-trolling said circuit controlling means whereby said circuit controllingmeans is rendered efiective only after the plant has reached apredetermined operating speed.

38. A control mechanism for an internal combustion engine having severalancillary systems the proper performance-oi which is necessaryto thecontinued proper operation of the engine, said mechanism comprising anumber of circuit controllirg devices each responsive to one of saidancillary systems, an engine stopping device, and means under thecontrol of said controlling devices for operating said engine stoppingdevice upon the operation of one of said devices in response to a defectin one of the ancillary systems, and a speed responsive means forrendering said last means inoperative until the engine has reached apredetermined speed.

39. The combination with a plurality of circuit controlling devicesoperatively connected with certaln ancillary systems of an internalcombustion engine, of means efiective only after an elapse of time forshutting down the engine, said means being under the control of saidcircuit controlling devices, and other means efiective only when theengine is running for rendering said circuit controlling devicesoperative.

40. The combination with a plurality of circuit controlling devicesoperatively connected with certain ancillary systems of an internalcombustion engine, of a speed-responsive means operated by the engine,means effective only after an elapse of time for shutting down theengine, said means being under the control of said circuit controllingdevices, said circuit controlling devices in turn being under thecontrol oi said speed-responsive means.

41. Acontrol system for an engine wherein the engine has an ancillaryfluid system, the maintenance of which is necessary to the continuedproper operation of the engine comprising a control device operativelyconnected into said fluid system and responsive to a, defect in saidsystem, means comprising an engine cut-on device and a timed controlelement therefor eflective only after a predetermined period of time forstopping the engine, said means being under the control oi said controldevice whereby theengine is stopped in a predetermlnedtime intervalafter a defect occurs in the fluid ystem.

prising a control device operatively connected into said fluid systemand responsive to a defect in said system, means efiective only after aore,- determined perlod of time for stopping the engine, means beingunder the control of said control device whereby the engine is stoppedin a predeterminecl time interval alter a defect occurs in the fluidsystem, and of means thereby said control device is rendered operativeonly while the engine is running.

. 43. An engine control system comprlsingan in'- (heating panel havingsignals thereon for indieating the condition of certain ancillary fluidsystems associated with the engine, means operable upon the starting ofthe engine for initially energizing the panel and upon the closing downof the engine for deenergizing the panel, an engine-stopping unit, andmeans in circuit with the signals for stopping the engine only after apredetermined lapse of time after any one of said signals indicates adefect in the ancillary system to which it responds.

44. A control mechanism for an internal combustion engine having severalancillary systems the proper performance of which is necessary to thecontinued proper operation of the engine, said control mechanismcomprising a number of cir-l cuit controlling devices each connectedwith and responsive to one of said ancillary systems, an engine-stoppingdevice, and means efiective only ter a predetermined lapse of time andunder the control of each of. said controlling devices for operatingsaid engine-stopping device when a defeet develops during the operation0! the engine in any of said ancillary systems to which the controllingdevices respond.

45. A control mechanism for an internal combustion engine having severalancillary systems the proper performance of which is necessary to thecontinued proper operation of the engine, said control mechanismcomprising a number 01' cucuit controlling devices each connected withand responsive to one of said ancillary systems, an engine-stoppingmeans, means efiective only after an elapsed period of time and underthe control of'each of said controlling devices for operating saidengine-stopping means when a defect develops during the operation of theengine in any of said ancillary systems to which the controlling devicesrespond, and means whereby the controlling devices are renderedefiective only while the engine is running. V

GEORGE D. POGUE.

